Using antarctic Dome C site and simultaneous nadir overpass observations for monitoring radiometric performance of NPP VIIRS instrument

In this study, two methods were used to evaluate radiometric calibration of the VIIRS sensor data records: (1) imaging of radiometrically stable Earth´s surfaces and (2) SNO (Simultaneous Nadir Overpass) observations by VIIRS and other satellite instruments. Measurements acquired by VIIRS at the stable Dome C calibration site in Antarctica confirm that a faster-than-expected degradation of the radiometric response occurs for selected spectral bands in the visible and near-infrared region, with other bands remaining stable. SNO comparisons with MODIS show that the implemented regular updates of the radiometric calibration coefficients have stabilized the calibration and that the VIIRS and MODIS measurements are in agreement.